From Europe to the Middle East, Asia to the Americas, governments and developers are reexamining what it means to provide dignified, affordable housing—and in many cases, they're getting creative.

Witness the majestic beauty of Saudi Arabia, home to the two holiest mosques in Islam—Masjid al-Haram in Makkah and Al-Masjid an-Nabawi in Madinah. A breathtaking look at the spiritual heart of the ...